Aggregates Manager

October 2013

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by Bill Langer
Bill Langer
is a consulting
research geologist
who spent 41 years with
the U.S. Geological Survey
before starting his own business.
He can be reached at
Bill_Langer@hotmail.com
In Stone
A VISIT TO THE
Dentist
Fluorspar mining endures trials and tribulations that make a geologist wince.
Y
ou know the drill. I was reclining in the dentist chair while a hygienist jabbed a sharp pick into my gums. She
paused and asked: "So you're a geologist. Do you look for gold?"
"No," I answered. "I study industrial minerals, like fluorite, which is used to make the fluorine you put on my
teeth."
I hoped she would continue the dialog and stop jabbing my gums. Besides, I love to talk about fluorspar because it exemplifies the trials and tribulations of industrial mineral development.
Fluorspar, like most industrial minerals, has a relatively low value compared with metallic ores mined under similar conditions. The margins of profit are small, and it commonly requires exceptionally good management to profitably conduct
any fluorspar (or most other industrial mineral) mining operation.
During the late 1800s, fluorspar was used chiefly in the manufacture of opalescent glass and
the preparation of fluoride-bearing chemical compounds. However, in the early 1900s, the use
of fluorspar increased when it replaced some of the limestone as a flux in the manufacture of
open-hearth steel.
Most steel production was located in the contiguous states of Pennsylvania, Ohio, Indiana,
and Illinois. Fluorspar deposits in Illinois and Kentucky that were near those markets and were
accessible to water or rail transportation had a huge advantage over those not so favorably
situated. So, while there is high-grade fluorspar in many western states, during the early 1900s,
their development was handicapped by the costs of long transport.
The quantity of fluorspar in a deposit is critical. During the early 1900s, a commercial deAlthough the last U.S. fluorite mine closed in 1995,
posit needed to produce at least a railcar load of marketable fluorspar a day and have at least
mining is expected to resume in Kentucky.
a 15-year life. Unscrupulous promoters swindled prospective producers out of large sums of
money for the purchase of leases on properties that did not contain fluorspar in sufficient quantity to warrant development.
Fluorspar may contain impurities that have to be eliminated for many uses. A log washer commonly was used to clean
fluorspar, and a convenient supply of water was essential. In arid portions of the West, fluorspar was cleaned by hand cobbing, which entailed much manpower and large amounts of waste. This further reduced the competiveness of western
fluorspar operations.
During the second quarter of the 19th century, the production of steel continued to drive the fluorspar market, but new
applications continued to be developed, including CFC (Freon) used in refrigerators and air conditioners. Meanwhile,
cheaper imports replaced U.S. production, and, by mid-century, over a quarter of the fluorspar used in the United States
was imported.
During the third quarter of the 20th century, the markets for fluorspar exploded. Fluorine found its way into applications
including aerosols, anesthesia, plastics, rubber, satellites, Teflon, and toothpaste. The list of uses kept getting longer and
longer. During 1974, the demand for fluorspar peaked, but 88 percent of the demand was met by imports.
During the last quarter of the 20th century, fluorspar's use in steelmaking decreased dramatically, and the production of
CFC was stopped because of its impact on the ozone. The last U.S. fluorite mine closed in 1995, signaling the end of 158
years of U.S. fluorite mining.
Today, we are totally dependent on imports of fluorspar, a mineral which once was deemed vital to the nation for security and economic reasons. The good news...mining is expected to begin again in Kentucky.
Did I tell you the hygienist's response to my mention of fluorspar? Jab, jab, jab! If only I had studied gold.
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